Traffic signal



June 940- F. H. RICHTERKESSING 2,204,228

TRAFFIC SIGNAL Filed Aug. 24

IN V EN TOR. KICHTERKESSMQ ATTORNEY.

Patented June 11, 1940 UNITED STATES PATENT rsice TRAFFIC SIGNAL Kentucky Application August 24, 1928, Serial No. 301,799 Renewed June 18, 1934 Claims.

My invention relates to the control of electrically operated traific signals primarily intended for use at the intersections of two thoroughfares.

The main object of my invention is to provide a means wherein an electric car approaching the intersection will take control of the traffic signal to favor the preferential movement of the car. In other words, the traffic signal will be displaying stop and proceed indications periodically until a car enters a selected proxim ity to the intersection, wherein the periodic control of the traffic signal indications will be interrupted to cause a prolonged display of a pro ceed indication, on the electric line and a red stop indication for intersection traflic, for the direct purpose of expediting the movement of the car and eliminating the congestion of traffic in the front of the car. The system is so arranged that the periodic control will be restored a soon as the car passes the intersection.

It will be apparent that by means of a series of such installations throughout the route of travel of an electric car, the car would be enabled to attain an express schedule with a maximum of protection which is a very essential factor when cars increase their average speed.

Briefly, it is the object of my invention to produce a trafiic signal system primarily intended to have a periodic display of its indications, but equipped with means, automatically controlled by the movement of a vehicle to prolong or control the display of a desired indication.

Another object of my invention is to produce 5 a system that works irrespective of the vehicle using power or not, the system as hereinafter described.

My invention resides in a new and novel combinaticn, the construction and relation of varione electrically operated switches, circuits and other parts hereinafter more fully described and disclosed in the drawing.

In the drawing accompanying my specification:

The single figure is a schematic drawing disclosing the general principles employed in my system.

My invention is intended primarily to be con trolled by cars that are operated by means of an overhead trolley wheel or current collector WI mounted on a car by means of a trolley pole, ale

though it may be controlled by vehicles which are operated by other methods.

In the system shown in. Fig. l, the letter 1) represents a trolley wire or conductor. Posi (or. was?) tioned adjacent the trolley wire or conductor D are trolley contactors 3A and 5A which are normally insulated therefrom, but are electrically connected thereto, when the current collector WI engages the trolley contactors 3A and 5A 5 respectively. The trolley contactor 3A is mount ed on the trolleywire D and is placed within a selected proximity on the approach side of the intersection represented in the drawing by N, E; S, W. Contactor 5A is mounted on the trolley wire D, on the far side of the intersection. At the intersection the letters TS represent a traffic signal for periodically displaying stop, caution and proceed indications for the W, E L electric line trafiic and the intersecting, N, S traffic.

I also employ an electrically operated relay R provided with two operating coils A and C, and each are energized to effect an operation of the contact plunger P when a car passes under the 29 trolley contactors 3A. and 5A. The plunger P of relay R is equipped with a contact ring A! that normally engages contacts 34 and 35, and is brought into this position by the energization of the coil 0. When the coil A is energized the 25 contact plunger P is shifted, and the contact ring Al is brought into contact engagement with contacts I 4 and 2! and out of contact engagement with contacts 34 and 35.

I also employ in this system a motor driven time element device for controlling the circuits for the periodical display of the stop, caution and proceed signals. The letter M represents a single phase alternating current induction mo tor and is equipped with a constant potential 5 field coil H and controlling field coils represented by J and K. The motor M is equipped with a copper or aluminum disc M, and the principle of the operation of such a motor is well known to those skilled in the art. The magnetic field pro- 0 duced by the constant potential and controlling field coils combine to form a rotating field; that is, the relation of these two fields for a"complete cycle by one-quarter periods of the same, is approximately a 90 degree lag of one over 45 the other. This continuous motion of the field induces eddycurrents in the copper or aluminum disc 14, which react to produce rotation in the same manner as in the rotor of an induction motor. Since the rotation produced by the ro- Q tary field is a combination of the constant potential and controlling fields, it can be readily seen that the removal or reversal of one of the fields, namely the controlling field, would stop the disc or cause the disc to run in a reversed direction.

In the system herein described and disclosed, I take advantage of this novel feature which plays an important part in the advancement of this art. 'It is well known to those skilled in the art that while the motor M is in a running condition, if the coil terminals of the controlling field coils J and K were short circuited, the collapsing of the controlling field and the rising of the constant potential field would react in a manner to retard and practically instantly stop the rotation of the disc, and as the coils of the controlling field J and K are short circuited, they would act as a shading coil and their field and the constant potential field would react in such a manner as to produce a reversal in the former direction of the disc. The disc 74 drives the controller segments 5|, 52, 53 and 54, through the shaft 55. With reference to the drawing, it can be clearly seen how the rotation of the cam segments in the direction of the arrow 56 pr0- duce a subsequent opening and closing of the various contacts controlling the circuits of the signal indications, and do not believe that a further explanation of how this is accomplished is necessary at this point, but will be taken care of more completely in a further detailed description.

The dotted outline figure TS is a symbolic representation of a traffic signal, housing three decks of signal indications to display in four directions. In the upper deck, the red lenses 62 and 63 that face N and S on the intersection, and the green lenses 64 and that face W and E, on electric line, have a common light source represented by L l. In the center deck the four lenses 55, El, 68, and 69 display an amber or caution indication and each is provided with an independent light source, lens fit having a light source represented by Li, lens 6'! having a light source represented by L3, lens (it having a light source represented by L2 and lens 69 having a light source represented by L. These indications, however, are not displayed simultaneously, but are displayed at intervals that will be more clearly described in a later description. In the lower deck the green lenses H3 and H that face N and S on the intersection and the red lenses l2 and 73 that face W and. E on the electric line, have a common light source represented by L5. For clarity of the description each of the three decks are shown in a plan view, and this must be taken into consideration when the signal system is described so that the signal indications will be given for their proper directions.

The indications of the trafilc signal are normally displaying periodically; that is, each signal indication displays a certain predetermined time before the display of another signal indication o curs, all of which occurs in a definite sequence of a predetermined cycle. Starting for instance at an arbitrarily selected time of the cycle, we have a displayal-of a green signal in both directions for the W and E electric line traiiic, and a displayal of a red signal in both directions for the N and S intersecting traffic, the circuit for these indications being completed from the positive side of the line BX, thru wire 3, wire 5, wire 6, contact arm 23 of the motor driven time element, contact 24 of contact arm 23, contact 25 of the stationary contact arm 26, thru the stationary contact arm 26, wire 21, to the signal lamp L4, which is a common light source for the four indications, wire ll, wire l6, wire i5, to the common return of the line CX. With reference to the drawing it wi l be seen that these indications will c0ntinue to display until the cam segment 5i permits the contact arm 23 to disengage the contacts 24 and 25, which is, for one half of the total cycle. It will also be noted, that just as the cam segment 5i nears the end of its period, the cam 52 embraces the contact arm 28 of the motor driven time element, and causes contacts 29 and 3-3 to be brought into contact engagement, resulting in a displayal of a caution signal or a short interval indication to warn the moving electric line traflic that a change is about to be made in the signal indications. It will be Well to note that this indication is not given to all four sets of the trafiic, but to the traffic that is in motion only, and is given with the green proceed electric line signal indicating. The circuit for caution signal for the moving W, E electric line traffic being complcted from the positive side of the line BX, thru wire 3, wire 5, wire "l, wire 8, contact arm 28 of the motor driven time element, contact 29 of contact arm 28, contact 30 of the stationary contact arm 3i, thru the stationary contact arm 3!, wire 32, wire 33, contact 34 of relay R, thru the contact .ring Al on the plunger P of relay R, contact 35 of relay R, wire 36, Wire 37, to the lamp L which is the light source for lens 69 facing the W electric line traffic. It will be noted that wire 3% connects two branch circuits, oneconnection to wire 3'! as described and the other to wire 33 which feeds the light source for the lens facing the E electric line trafiic. The circuit for this being completed from the wire 3'! to the branch wire 38, thru wire 38 to lamp L2, which is a light source for lens 68 facing the E electric line trafiic. Both lamps L and L2 have a common connection to the common return thru wire 19 feeding to Wire i3, thru wire 13, wire I6, wire 15, to the common return of the line CX. Cams El and 52 disengage their respective contact arms simultaneously, and instant to this operation cam 54 embraces the contact arm -46 of the motor driven time element and causes contacts il and 48 to be brought into contact engagement. These opera tions resulted in the former described indications going to darkness and the display of a red indication for the W, E electric line trafiic and a green indication for the N, S intersecting traffic. It will be noted that the display of these indications caused the moving trafiic to come to a stop and the trains that was at stop to be permitted to proceed. The circuit for the latter indications being completed from the positive side of the line BX thru wire 3, wire :5, wire 7, wire 9, wire H, contact arm id of the motor driven time element, contact 4'! of contact arm 66, contact 48 of the stationary contact arm 49, thru the stationary contact arm 49, wire 5%, to the signal lamp L5 which is a common light source for the four indi cations, wire 20, wire Hi, wire it, to the common return of the line CX.

With reference to the drawing, it will be seen that these indications will continue to display until the cam segment 54 permits the contact a rm 66 to disengage the contacts 4? and 48, which is. as shown one half of the total cycle. It will also be noted that just as the cam segment 5i nears the end of its period, the cam 53 embraces the. contact arm 39 of the motor driven time element causing the contacts 40 and ll to be brought into contact engagement, and resulting in a displayal of a caution signal or a short interval indication to warn the moving intersecting trafiic that a change is about to be made in the signal indications. It will be well to note that this indicat1on is not given to all four sets of traffic, but to the traffic that is in motion only, and is given with the green proceed signal indicating. The circuit for the caution indication for the moving N, S intersecting trafilc being completed from the positive side of the line BX thru wire I3, wire 5, wire I, wire 9, wire Ill, contact arm 39 of the motor driven element, contact 40 of contact arm 39, contact II of the stationary contact arm 42, thru the stationary contact arm 42, wire 43, wire 44, to lamp LI, which is the light source for lens 66 facing the N intersecting traffic. It will be noted that wire 43 connects two branch circuits, one connection to wire 44 as described and the other to wire 45 which feeds the light source for the lens facing the S intersecting traflic. The circuit for this being completed from wire 43 to the branch wire 45, thru wire 45 to lamp L3 which is the light source for lens 61 facing the S intersecting trafiic. Both lamps LI and L3 having a common connection to the common return thru wire I9 feeding to wire I8, thru wire I8, wire I5, Wire I5, to the common return of the line CX. Cams 53 and 54 disengage their respective contact arms simultaneously and instant to this operation cam 5| embraces the contact arm 23 of the motor driven time element, and the signal indications are continuously displayed in same cycle as just described.

When the current collector WI engages the trolley contactor 3A, the contactor will be electrically connected and of the same potential as the trolley wire, and the coil A of relay R will be energized and shift the plunger P of relay R, bringing the contact ring AI into contact engagement with contacts I4 and 2|, andv out of contact engagement with contacts 34 and 35. The circuit for the energization of coil A being completed from the trolley wire D, thru the current collector WI, thru the contact strip of the trolley contactor 3E, wire 58. coil A of relay R, wire 59 to ground G. As soon as the current collector disengages the trolley contactor, the coil A of relay R will become deenergized but the plunger P will remain in the shifted position. At this point it will be well to note the circuit of the motor M of the motor driven time element device. H of the motor M is connected directly across the line. This circuit being completed from the positive side of the line BX thru wire I, field coil H of motor M, wire 2, to the common return of the line OK. The controlling field coils J and K of the motor M are connected in series. and in series with the resistor RI, and connected across the line. This circuit being completed from the positive side of the line BX thru wire 3, wire 4, field coil J, field coil K, wire I2, resistor unit RI, wire I5, to the common return of the line CX. The shifting of the plunger P of relay R resulted in the opening of contacts 34 and 35 of relay R, that normally completed the caution signal circuit for the W, E electric line traffic, and closed contacts I4 and 2| thru the contact ring AI. This operation did not affect the signal display, however, unless the signal was displaying the electric line caution indication, or not until the timer passed thru the necessary cycle to establish this circuit. After the automatic motor driven time element device passed thru the necessary cycle and encountered the display of a green prom-red" indication for the W, E electric line traffic and a display of a red stop indication for the N, S, intersecting traffic, the signal indications continued to display under the influence of the automatic motor The constant potential field coil driven time element until the time for the display of the caution indication for the W, E electric line traffic.

As soon as the contacts closed, however, the caution signals werenot displayed, as the circuit was opened thru the opening of contacts 34 and 35 of relay R, as hereto-fore described. But the closure of this circuit, at the automatic motor driven time element, resulted in a short circuit of the controlling field coils J and K of the motor M, thru the resistance unit R1, and the motor was stopped; that is, it continued to oscillate at this point, running forwards and backwards, opening and closing the contacts, on the motor driven time element, controlling this circuit. This circuit was under the control of cam 52 on the automatic motor driven time element, and was completed from the positive side of the line BX, thru wire 3, wire 5, wire I, wire 8, contact arm 28 of the automatic motor driven time element, contact 29 of contact arm 28, contact 30 of the stationary contact arm 3|, thru the stationary contact arm 3i, wire 32, wire 22, contact 2| of relay R, contact ring AI of plunger P on relay R, contact I4 of relay R, wire I3, resistance unit RI, wire I5 to the common return of the line CX. The closure of contacts 29 and 30, resulted in placing positive thru wire I2 on the controlling field coil K, and as the other coil J, which is in series with coil K, is constantly connected to the same source thru wires 4 and 3, no current flowed in the controlling field coil circuit, and as heretofore described the motor reversed its direction as shown by the arrow 51. The reversing of the motor rotation resulted in an opening of the contacts controlling the shunt circuit, and permitted the motor to run forward until the contacts were again closed. It can be seen that this condition would continue as long as the shunt circuit was established in this manner, and retain the display of a green signal for the W, E electric line traffic and a red stop indication for the intersecting traffic, however, as soon as it would be removed the motor would continue to run its normal direction as shown by the arrow 56. The purpose of having the motor reverse its direction is to always have a complete display of the caution indication when the motor control is restored. It can be seen that some time is involved in bringingthe motor disc 14 to stop, and this time is absorbed in the W, E electric line caution signal display time, after the contacts controlling the circuit were closed. It can be seen that since the total time for this signal display is very short,

that any time subtracted from it would be very noticeable, and since this time is variable would defeat its designated purpose. Therefore, by stopping and reversing the motor, as described and employed in this system, irrespective of where the motor is stopped or caused to be stopped by the application of a shunt under the control of the caution signal contacts, a full caution signal display would be rendered when the system is restored to its periodic control.

After the traveling current collector WI travels its course, it passes the intersecting N, S, W, E and comes into contact engagement with the trolley contactor 5A mounted on the trolley wire D. The contact engagement of the current collector WI, and trolley contactor 5A resulted in a circuit being completed from the trolley wire D, thru the current collector W I, thru the contact strip of trolley contactor 5A, wire 59], coil C of relay R, wire (H to ground G, and the 0011 C was energized and the plunger P of relay R was shifted. The movement ofthe plunger P of relay R, removed the contact engagement of the con tact ring AI of relay R with contacts I4 and 2|, and brought it into contact engagement with contacts 34 and 35. This operation removed the shunt circuit on the controlling field coils J and K that was completed thru the contacts 2! and M, and established an immediate display of a caution signal for the W, E electric line traffic, the circuit being completed from the positive side of the line BX thru wire 3, wire 5, wire l, wire 8. contact arm 28 of the automatic motor driven time element, contact 29 of contact arm 28, contact 39 of the stationary contact arm 3!, thru the stationary contact arm 3|, wire 32, wire 33, contact 34 of relay R, contact ring A! of plunger P on relay R, contact 35 of relay R, wire 36, wire 31 to lamp L which is a light source for lens 69 facing the W electric line trafiic, and also thru wire 38, which taps to wire 36 at its terminating point with wire 37, to lamp L2 which is a source for lens 68 facing the E electric line traffic. Both lamps L and L2 have a common connection to the return wire thru wire it, to Wire l8, thru wire i8, wire it, wire 45, to the common return of the line CX. The movement of the current collector Wi past the trolley contactcr 5A resulted in the system being restored to a normal; that is the signal indications would now be displayed periodically as heretofore described until a following car would take control of the automatic motor driven time element to prolong the green proceed" indication for its course of travel, until it passed the street intersecton.

It would be well to note that in this system the periodic control of the signal indication is disturbed only when the running time of the car from trolley contactor 3A to trolley contactor 5A is greater than the green period of the signal for the W, E electric line traffic, or dependent upon what time of the display, it entered the said section. In any case the car will take control of the signal for an added time long enough to permit its passage over the intersection, wherein the signal will immediately display an amber caution indication and then display a red stop indication for the W, E electric line traflic and a green proceed indication for the NS intersecting traflic under the influence of the automatic motor driven time element.

it is obvious to those skilled in the art, that although the system is shown and described in the drawing and specification for operation on a single track electric line, that the system is also operable on a double track electric line.

There are, of course, modifications and arrangements of the parts and circuits which may be made from that shown in the above disclosure and which will still fall within the scope of my invention.

I claim:

1. A traflic signal system arranged at the intersection of a main highway and a crossroad for regulating trafiic, said system comprising a plurality of signal circuits, one circuit including a signal to indicate stop and another to inclicate go, a normally active time controlled switch means included in the said circuit for alternately opening and closing same cyclically, vehicle operated devices in the main highway to be consecutively operated by a vehicle, and means operated by said devices for rendering said time aaoaees controlled switch means temporarily inactive and retaining the said go signal for the main highway.

2. A traffic signaling system for regulating traffic on interfering traflic lanes; said system comprising a plurality of signal circuits, one circuit including a signal to indicate stop and another to indicate go, a normally active time controlled switch means included in the said circuit for alternately opening and closing same cyclically, a vehicle operated device on one of the said traffic lanes, means operated by said device for rendering said time controlled switch means inactive and retaining the said go signal for the last said traiific lane, a second vehicle actuated device on the last said traffic lane, and means operated by said second device to restore the said system and time controlled switch to their normal active condition.

A right-of-way indicating device for interfering traffic lanes; controller means for normally periodically shifting the right-of-way indication from one trafiic lane to the other; means to arrest the controller so as to maintain the right-of-way indication on one of said trafficlanes; means including a vehicle operated device on the last said traffic lane to operate the controller arresting means to maintain the right-ofway indication on the last said trafic lane, and means including a second vehicular operated device on the last said tramc lane to restore the said controller arresting means to normal and to re-establish the periodic control of the said indications by the controller.

4., In a traiiic signaling device; an electrically operated right-of way indicating device for intersecting thoroughfares; an electrically opei ated motor normally operating, controller means driven by the said motor; circuit connections between the said controller and right-ofway indicating device, for normally shifting the said right-of-way indication from one thoroughfare to the other; a trafiic responsive means for one of said thoroughfares having one condition of operation when traiiic on the said thoroughfare approaching the intersection and is within a certain distance thereof; and a second condition of operation for all other positions of traffic on the last said thoroughfare with respect to the intersection; and means controlled jointly by the traihc'responsive means and the controller means for stopping operation of the said motor so as to retain the right-of'way indication to the last said thoroughfare when said traffic responsive means is in the first condition of operation and for restoring operation of the said motor when the traflic responsive means is in said second condition.

5. A trafiic control system to be applied at the intersection of vehicle lanes and. including sig naling means for alternately according and in terrupting right-of-way to the said lanes, normally active timer means for timing the alternating periods of right-of-way, and means responsive to the presence of a vehicle in one of said lanes approaching the intersection, for arresting the operation. of the said timer to retain the right-of-way accorded to the said one lane, and means responsive the instant the vehicle clears the intersection to restore the timer to its nor mally active condition.

6. A trafiic control system to be applied at the intersection of vehicle lanes and including signaling means for alternately according and interrupting right-of-way to the said lanes, normally active timer means for timing the alternatelectric ing periods of right-of-Way, and means responsive to the presence of a vehicle in one of said lanes approaching the intersection, for arresting the operation of the said timer to retain the right of-way accorded to the said one lane, and means responsive the instant the vehicle clears the intersection to restore the timerto its normally active condition, and means for delaying the establishment of right-oi-way on the other said traflic lane for a predetermined time after the said timer is restored to its normally active condition.

7. A vehicle-responsive control for stop and go signals for interfering traffic lanes comprising, in combination, a normally-energized electric motor; means operated by the said motor for actuating said signals in accordance with a predetermined cycle; a vehicle-actuated device in one of said lanes; relay means operating in response to an actuation of the said device; a normally-open relay switch closed by the operation of the said relay means; a normally-open control switch operated by the said motor, and closed during a latter portion only of the go signal actuation for the said one lane; and a shunt circuit for de-energizing the said motor including the said control switch and said relay switch.

8. In a traflic control system comprising stop and go signals for interfering traflic lanes; an motor normally operating; means operated by the said motor for actuating the said signals in accordance with a predetermined cycle; control means operated by the said motor during a latter portion only of each actuation of the go signal for one of said lanes; a vehicleactuated device in the said one lane; relay means operating in response to an actuation of the said device; and means, controlled jointly by the operation of the said control means and the operation of the said relay means, for stopping operation of the said motor so as to retain actuation of the go signal on the said one lane.

9. In a traffic control system comprising stop and go signals for interfering trafiic lanes; an electric motor normally operating; means operated by the said motor for actuating the said signals in accordance with a predetermined cycle; a vehicle-actuated device in one of said lanes; and means, operating in response to any actuation of the said device and cooperating with the first mentioned means during a latter portion only of the actuation of the go signal on the said one lane, for stopping operation of the said motor so as to retain actuation of the go signal on the said one lane.

10. In a traffic control system. comprising stop and go signals for interfering traffic lanes; timing means alternately displaying said signals to each of said lanes for predetermined times for the control of traffic; control means operated by the said timing means during a latter portion only of each display of the go signal for one of the said lanes; a vehicle-actuated de- Vice in the said one lane; relay means operating in response to an actuation of the said device; and means controlled jointly by the operation of the said relay means and the operation of the said control means for cooperating with the first named means to extend the time of display of the go signal on the said one lane beyond the time predetermined by the first named means, whereby extension in the time of display of the said go signal on the said one lane is held in abeyance until the said control means is operated, and provided only when the said relay means is operating at such time.

FRANK H, RICH'I'ERKESSING. 

